In computer-based apparatuses, touchscreens are being increasingly employed to detect operating commands. What is referred to as a touchscreen is a display device which is adapted, on the one hand, to display pictorial information and, on the other hand, detect position(s) of one or more objects interacting with the touchscreen, for example touching the touchscreen. With the touchscreen, the user can immediately select an object displayed on the touchscreen without the aid of conventional input means, such as computer keyboards, joysticks or computer mice. The operation of the computer-based apparatus is thereby facilitated. Moreover, touchscreens usually feature easily cleaned outer surfaces, which is why they are preferred over conventional input means.
In order to input an operating command, the user may touch a touch-sensitive surface of the touchscreen at a place at which a graphic element representing the operating command is displayed. The graphic element may be, for example, a wastepaper basket or a control button with a textual explanation representing the command, e.g., “Laser ON” (i.e. switch on the laser). If, for example, the wastepaper basket is selected, i.e. the user touches the touchscreen in the region of the wastepaper basket, previously selected data or files may be deleted, and if the control button, “Laser ON” is selected, a laser may be put into an operating state in which a laser beam is emitted.
Commands of this type may have irreversible consequences, since deleted data or, in the above example, tissue treated by the laser beam cannot be readily restored. In order to avoid operating errors in the case of irreversible or safety-critical commands, a hurdle to operating errors may be provided whereby a command input has to be confirmed by an additional input. To this end, for example, a safety query may be displayed on the display of the touchscreen, enabling the user to confirm or cancel the operating command.
By way of example, reference is made in this regard to known art, e.g., by Microsoft applications, where an input window displayed on a graphical user interface of a touchscreen can be seen, by means of which the user may be prompted, for example by a program executed on the computer-based apparatus, to confirm a command proposed by the apparatus. One in the art is familiar with a question like “Delete all measurement data?”, which may be displayed on the touchscreen. In order to answer this question, the user may have the option to confirm the proposed command by selecting an “OK”, “Yes” or equivalent control button (equivalent in the sense of a semantic relationship to “OK” or “Yes”) or reject it by selecting a “Cancel”, “No” or equivalent control button. After selection of the control button, however, the associated operation (e.g., deletion operation) may not be carried out directly. Instead, the user may be prompted with a safety question to confirm the operation; for example, a query field “Delete all measurement data. Are you sure?” may be displayed. Only after the user has answered the safety question by selecting/activating an associated control box displayed on the touchscreen, is the measurement data deleted in accordance with the command.
This kind of confirmation of an operating command is comparatively cumbersome and the duration of the entire command input is relatively long.
Against this background, it is an object of the present invention to provide an apparatus and a method for controlling such an apparatus which are distinguished by a user-friendly and at the same time safe operation.